Apparatus for drying grain



March 9, 1937. K. DIENST 2,073,553

' APPARATUS FOR DRYING GRAIN Fild Nov. 25, 1935 3 Sheets-she t i Karl Dlmwt lweutor I A-ttorlvey Match 9, 1937.

K. DIENST APPARATUS FOR DRYING GRAIN Filed Nov. 25, 1935 3 Sheets-Sheet 2 FIG.2

KarlD Ida/1 A III! u U March 9, 1937. DIENST 2,073,553

- APPARATUS FOR DRYING GRAIN Filed NOV. 25, 1935 3 Sheets-Sheet 5 i A f xi f 10* 1 700 T 7 I 3/ 50 5 I 60 Ill 7 1 3 :5 9

' 1 I g i 55 57 56 1 I Karl Deusi' Atta may Patented M... a, 1937 UNITED, STATES 2,013,553 APPARATUS FOR DRYING GRAIN -Karl Dicnst, Hildesheim, Germany Application November 25, 1935, Serial No. 51,533

In GermanyJune 26, 1933 15 claims, (Cl. 34-34) My invention relates to improvements in apparatus for drying grain, and more particularly in apparatus of the type comprising an upright grain drying shaft having a chamber for sup- 5 plying the grain to be dried at its top, a chamber for removing the dry material at its bottom, and an intermediate vacuum chamber provided with heating means. The vacuum chamber contains at the same time and under the same vacuum the-grain to be dried, the grain in the drying state and the dried grain. One of the objects of the improvements is to provide an apparatus of this type by means of which the grain is dried under vacuum continuously and in uninterrupted operation within a short time and at comparatively low temperature, the power needed for operating the apparatus being likewise small. The

apparatus may be used for drying grain for storing, and it may also be used for drying grain which has been washed or moistened, and which is to be prepared for grinding.

With the aforesaid object in view my invention consists in dividing the said intermediate vacuum chamber located between the supply and delivery chambers into three sections, the uppermost section being constructed for storing the grain prior to drying, the intermediate section being provided with heating and evacuating means and having the function of vaporizing the 3" humidity of the grain, and the lowermost section being constructed for receiving the grain after drying, the grain being continuously removed from the said intermediate or vaporizing section so that it continuously drizzles through the same.

Another object of the improvements is to provide an apparatus of the class indicated in which the vacuum within the vacuum chamber is not materially affected by the supplying and delivering operations, and with this object in view I provide subsidiary chambers intermediate the said vacuum chamber and the chambers located respectively above and below the same, the said subsidiary'chambers being connected with evac uating means and with means for temporarily connecting the same with the adjacent cham bers located respectively above and below the same.

In the operation of the apparatus it is important that the valves or gates for connecting and disconnecting the chambers be constructed i so that the grain is transferred from onechamber to the other one without permitting the ac- I cess of outer air to the vacuum chamber or chambers.

For the purpose of explaining the invention several examples embodying the same have been shown in the accompanying drawings in which the same reference'characters have been used in all'the views to indicate corresponding parts. In said drawings Fig. Iris 9. vertical section oi an apparatus with mechanically operated valves,

Fig. 2 is a fragmentary sectional elevation on a larger scale showing the heated intermediate section of the vacuum chamber of the apparatus illustrated in Fig. l, the said section being taken on the line 22 of Fig. 1 and on a plane perwhich subsidiary chambers are provided respectively between the supplying and delivering chambers and the vacuum chamber,

Fig. 7 is a sectional elevation similar to the one illustrated in Fig. 4 and showing the valve provided in the apparatus illustrated in F1 8 6 between the uppermost supplying chamber rindthe adjacent subsidiary chamber,

' Fig. 8 is a sectional elevation similar to the one illustrated in Fig. 4 and showing the valve intermediate the upper chamber and the vacuum chamber located below the same of an hydraulically driven apparatus illustrated in Fig. 6,

Figs. 9 and 10 are sectional elevations showing one of the valves of Fig. fi-controlling the supply of pressure fluid to the cylinders and pistons controlling the valves intermediate the chambers of the apparatus, the plugs 01 the valves being shown in different positions,

Fig. '11 is an elevation of the said valve viewed from the right in Fig. 10,

Fig. 12 is a detail view showing a rotary switch I of Fig. 6 forming a part of the mechanism controlling the valves of the apparatus,

Fig. 18 is a detail sectional elevation showing a modification of the device of Fig. 6 by the use or slide valves. I

As is shown in Fig. 1, the grain drying apparatus comprises a vertical sectional cylindrical shaft 2 which is mounted on pillars I, and which 5 a shaft section 5 is mounted which is open at its top and which has a downwardly tapering bottom |2 normally closed by a valve l5. To the shaft section 6 grain to be dried is supplied by means of a chute 8. The valves l5, l8 are iil tted in openings l3, H of the hopper shaped bottoms l2 and 3, as is best shown in Figs. 4 and 5. The

shaft sections 2, 4, and 5 and the bottom l2 of the shaft section 6 form a vacuum chamber which is closed all around, and which is adapted to be heated. In its uppermost or storage part the said vacuum chamber receives the grain to be dried, the said grain is supplied to the median part of the chamber which isprovided with the radiator l1, and the bottom part of the vacuum chamber which is provided by the shaft section 2 contains the dried material.

The radiator I1 is illustrated in detail in Figs. 2 and 3. It comprises a jacket or manifold l8 through which steam is supplied to the radiator elements, and a manifold IS in which the water of condensation is collected. Between the said manifolds l8 and 9 there are heating pipes 20 which are preferably oval in cross-section. The side walls 2| and 22 of the radiator H are perforated thus connectingthe grain located between the pipes 20with the main part of the vacuum chamber 2, 4, 5. For more readily removing the vapor from the body of grain located between the radiator elements roof shaped plates 23 are provided between the side walls 2| and 22 of the radiator. The vapor is collected below the said plates 23 and it is passed therefrom into the vacuum chamber 2, 4, 5 which is being evacuated through the pipe Ill. The bottom of the radiator l1 comprises four hoppers 24 which are adapted to be entirely or partly opened or closed by gates 25. The said gates are fixed to a stem 25 which is adapted to be shifted-endwise by means of a hand wheel 21. Thus by turning the said hand wheel all the gates 25 may be exactly and uniformly set into positions for opening the hoppers 24 as far as desired. The valve l5 ior'closing the opening I: of the bottom |2 of the upper chamber. 8 comprises a cylindrical portion 29, a conical head part 28 and an outwardly directed conical flange or skirt portion 30. The wall of the opening H of the-hopper 2 has a packing ring 32 embedded in a groove ill, the said packing ring cooperating with the cylindrical portion 29 of the valve l5 for prelimi narily closing the hopper. On a ring 34 placed around the opening l3 rubber rings are mounted which are fitted in dove-tailed annular grooves of the ring 34, and which are engaged by the flange 3|! of the valve body ,l5 when the valve is closed. The valve I5 is fixed toa stem 35 which extends all through the apparatus from the top to the bottom thereof, and which is screw-threaded at its top, a worm gear 36 being mounted on the said screw-threaded part of the stem for moving the same upwardly or'downwardly. ,At its bot- ;tom end the stem is provided with a flange 31 located withinthe valve body I5, a spring 38 being located between the said flange and the valve body by means of'which the valve I8 is yieldingsaid ly'placed on its seat for closing the opening I4 of the bottom 2. .At its bottom the valve body is closed by a disk 38 which is engaged by the flange 31 when the stem 35 is forced downwardly for opening the valve IS. The general shape of the valve I6 is similar to that of the valve l5.

The worm gearing 35 is engaged by a worm 45 to which rotary movement is imparted by means of an electro-motor 4|.

In the top part 501' the vacuum chamber 2, 4, 5 a plate 42 is pivotally mounted which isadapted to be elevated when the part 5 is empty by means of a weighted body 45 suspended from a rope 45 guided on rolls 44. The rope 43 is provided with a current reversing switch 46 by means of which the electro-motor 4| may be operated in one or the other direction, according as the plate 42 is held downwardly by the grain bearing thereon or directed upwardly when there is no grain within the part 5 of the vacuum chamber. When the grain isdelivered from the part 5 of the plate 42 is lifted by the weighted body 45, the position of l the switch 45 is reversed, and the electro-motor 4|, is likewise reversed for moving the valves l5 and I6 downwardly, so that a new supply of grain flows from the container 8 into the'section 5 of the vacuum chamber-2, 4', 5 and the dried grain flows from the lower part 2 of the vacuum chamber into the delivery chamber 41 from which it is removed by means of a screw conveyor 45.

After the top part 5 of the vacuum chamber has been filled completely or in part the plate 42 is directed downwardly, the weighted body 45 is elevated, and the switch 48 is reversed, so that now the stem 35 and the valves l5 and I6 are lifted and the chambers controlled thereby are closed.

The grain moving downwardly from the part 5 drizzles through the radiator I! while being heated, and it is delivered through the slits of the'hoppers 24 which are opened sufllciently by means of the gates 25, and into the bottom part 2 of the vacuum chamber.

The continuous and uni rm flow of the grain through the radiator and t e degree of drying of the grain within the heating chamber depend on the position of the gates 25 controlled by the hand wheel 21.

In Fig. 6 I have shown a modification in which subsidiary chambers 50 and 5| are provided respectively between the upper chamber 6 and the vacuum chamber 2 4 5 and between the said vacuum chamber and'the chamber 4! provided at the bottom of the apparatus. The upper chamber 55 is closed as against the vacuum chamber 2 4 5 by its bottom 52 and a valve 54 closing means of which they are connected to an evacuating device such as an air pump. The object is to permitvthe grain to be supplied to the'vacuum chamber and to be removed therefrom after drying without any access of outer air to the vacuum chamber. The grain which has passed from the supply chamber 6 and through the subsidiary chamber 55 into the vacuum chamber is closed as against the outer air while it is within the chamber 55, and the-said chamber is evacuated, so that practically no air is'carried into the vacuum chamber when the grain passes into 'the same. The chamber 5| is evacuated after air has got into the same by the valve 5'! being opened for the purpose of removing the grain fromthe chamber 5|, so that no air gets into the vacuum Therefore the vacuum chamber can be filled and emptied in rapid succession. Y

The valves I5 and 51 are simultaneously opened and closed while the valves 54 and I8 are in closed position, while the valves 54 and I6 are opened while the valves I5 and 51 are in closed position. Hydraulic means have been provided for operating the valves I5 ,'54, I8 and 51. As shown the valves are connected respectively with piston'rods 58 59 68 and 6| and pistons. 82, 83, 84, and 6,5, the said pistons being located in cylinders 88, 81, 58, and 89. To each of the said cylinders two pipes are connected, one of the pipes 18, 12, 14, and 16 being connected to the top parts of the said cylinders and the other pipes'1I, 13,

15, and 11 to the bottom parts thereof. The pipe 18 is connected with the pipe 11, and at their joint the said pipes are connected by a pipe 18 with a valve 19. The pipes Hand 18 are 'connected with the valve 19 through a short pipe 88. The pipe 12 is connected with the pipe 15, and both pipes are connected by a pipe 8| with a valve 82. The pipe 13 is connected with the pipe 14, and both pipes are connected with the valve 82 by a pipe 83. The valves 82 and 19 are symmetrical in construction, andthey are connected with each other by a pipe 84 and with a container 8.6 of pressure fluid through a pipe 85. ,The

pressure fluid from the said container is conveyed through a pipe 81 into a pump 88 the pres-' sure chamber ofwhich is connected by a pipe 89 with two branch pipes 98 and 9| connected with the valves 19 and 82. The pipes 83 and 9| are connected to the casing of the valve 82 within a transverse plane, and the pipes 8| and 84 are connected to the said valve 82 within another plane. 92 which is adapted to be rotated only through an angle of 90, andwhich comprises two passages 93 and 94. The passage 93 is located in the plane of the pipes 83 and 9|, and the passage 94 is located in the plane of the pipes 84 and 8|. Between the passages 93 and 94 a short groove 95 is madein the circumferential wall of the valve plug 92. From the pipe 9| a pipe 98 is branched off which opens into the valve casing 82 in the plane of the pipes 8| and 84, the said branch pipe being connected to the casing 82 at the rear of the point where the pipe 83 opens into the valve casing 82. From the pipe 83 a pipe 91 is branched oil which opens into the casing 82 at the rear of the plane of the pipes 8| and 84. At the rear of the opening of the said branch pipe 91 a branch pipe 98 opens into the valve casing, which branch pipe is connected with the pipe 84.

To the stem 99 of the plug 92. of the valve 82 a crank I88 is fixed (Fig. 6) which carries a pin I8| engaging in a longitudinal slot I82 of a rod I83. The said rod is acted uponby two springs I84 and I85 supported on a frame'I88. The said rod I83 is further'acted upon by two electro-' magnets I81 and I88 the terminals of which are connected by leads to a contact drum I89. The said contact drum is adapted to be rotated through the intermediary of a gear wheel H8 and a pinion II2 from an electro-motor III. To the said drum I89 two contacts 3 and H4 are 75 fixed (Fig. 12) which cooperate respectively with The said valve comprises a rotary plug and H8.

brushes II5 connected with the winding of the electromagnet I81 and brushes I I8 connected with the winding of the electromagnet I88, By the contact strip 3' a circuit including a lead 1 is closed. so that the electromagnet I81 is energized and'the cook 92 of the valve 82 is turned through the intermediary oi the rod I83 from the median'position in which the pipes 83', 9| and 8|, 84 are disconnected into the position shown in Fig. 9 in which pressure fluid is passed from the supply pipe 9|, the passage 93, the pipe83 and the pipe 13 below-thepiston 83 of the valve 54, thus elevating the said. valve upwardly and 'into a position in which the grain from the vacuum chamber 58 flows into the upper part 5 of the vacuum chamber 2 4 5 Simultaneously pressure fiuid flows through the pipe 14 into the cylinder 88 above the piston thereof, thus pull.- ing the valve I8 downwardly and permitting the dried grain from the lower part 2 of the vacuum chamber to. flow into the chamber It will be understood that both chambers 58 and 5| are evacuated. The pressure fluid which is' above the piston 83 of the valve 54 is delivered through the pipes 12 and 8|, the passage 94, and the passages 84, 85 into the pressure fiuid container 88. The pressure fiuid which is below the piston 84 likewise fiows through-the pipes and 8|, passage 94, the pipes 84 and 85 into the pressure fluid container 88. Upon further rotary movement of the contact drum I89 the contact strip 4 conthe pipes 89 and 9| flows through the branch pipe 1 96 ,and the passage 94 into the pipe 8| and from the-said pipe through the pipe 12 into\the cylindrical chamber above the piston 83 of the valve 54 .thus closing the said valve. The passage 93 is closed at its end. Simultaneously the pressure fiuidfiows throughthe pipe 15 into the cylindrical chamber below the piston 84 of the valve I6 and closes the said valve.- In both cases the expelled pressure-fluid flows throughthe pipes 13, 14, 83, the branch pipe 91, the groove 95, the branch pipes 98, the pipes 84, 85, and finally into the pressure fluid container 88. Therefore the vacuum chamber 2 4 5 is again closed as against the chambers 52 and 5|. After the contact strip ,4 has passed the brushes II8 the springs I84, I85 return the rod I83 of the valve 82 into initial position.

The valves I5 and 51 are controlled bythe valve 19 which is operated in the same way as the valve 82, the valves 19 and 82 being symmetrical to each other. The valve 19 is likewise electrically controlled by means of contact strips mounted on a drum 8. The said drum is likewise rotated by the pinion I I2 of the motor III.

The electromotor III and an electromotor II9 connected with :the pump 88 are controlled by a switch I28 which is operated by a hinged plate 42 through the intermediary of the rope 43 and the weighted body When the said weighted is closed.

Between theshaft of the electromotor III and the pinion II2 there is a clutch of known construction which upon a supplyof current to the motor permits only one rotation of the drums I89 its'bottom, a vacuum-chamber intermediate the I said top and bottom chambers, evacuating means slide valves may be provided, as is shown in Fig. 13.

In the opening I3 of the bottom I2 and in the.

opening 53 of the bottom 52 a cylindrical slide I2I is mounted which is fixed to the rod 35 extending through the apparatus. This cylindrical slide I2I is formed with passages I23 separated from one another by ribs I22, and the grain may be supplied from the chamber located above the bottom I2 through the said passages and into the chamber 50 when the cylindrical slide is in its lowermost position. At its bottom end the slide I2 Iis formed with passages I24 through whibh the grain contained within the chamber 50 gets into the upper part oi'the vacuum chamber when the cylindrical slide I2I is in the elevated position shown in Fig. 13. The cylindrical slide I2I is guided in sleeves I25 and I26 fixed respectively to the bottoms I2 and 52 To the upper bottom I2 a cap I2! is fixed by means of ribs I28, which cap covers the cylindrical slide and the passages I23 'thereoi when the cylindrical slide is not in its lowermost position. The delivery of the dried grain from the vacuum chamber and the subsidiary chamber located below the same may be controlled by a cylindrical slide I2I which may likewise be fixed to the rod 35 the construction of the said cylindrical slide I2I being symmetrical to that of the slide Just described. M

Also in this case by providing the subsidiary chambers 50 and-5| the material to be dried and the dried material may be supplied and removed at short intervals of time without the vacuum within the vacuum chamber 2 4 5 being broken.

I claim:

1. An apparatus for drying grain, comprisingan upright shaft having a grain supplying cham-' ber near its top, a grain delivering chamber near for said vacuum chamber, means for opening and closing said vacuum chamber relatively to said supplying chamber, the said vacuum chambercomprising three sections located one above the other and continuously communicating with one another, and heating means for the intermediate section, the uppermost section being constructed' for storing the grain, the intermediate section for evaporating the humidity of the grain, and the lowermost section for continuously receiving the dried material from the intermediate sectionl and automatic intermittently-acting means iorisupplying the grain to, be dried and for causing the dried grain to be delivered from said lowermost.

section in which said opening and closing means and said' intermittently-operating means each comprises a cylindrical vertically movableslidevalve.

2. An apparatus as claimed in claim -l,.in which the said shaft is provided with additional chamhers one located between the said grain supplying chamber and said vacuum chambevand the other one between the said vacuum chamber and lowermost chamber, and in which means are provided for evacuating the said additional chambers and connecting and disconnecting the same with the adjacent chambers located respectively above and below the same. i

3. An apparatus for drying grain, comprising an upright shaft having, a grain supplying cham- 55; near its top, a grain delivering chamber near its bottom, a vacuum chamber intermediate the said top and bottom chambers, evacuating means for said vacuum chamber, means for opening and closing said vacuum chamber relatively to' said supplying chamber, the said vacuum chamber comprising three sections located one above the other and continuously communicating with one another, and heating means for the intermediate and closing means and said meansfor supplying the grain to be dried and causing the dried grain to be delivered from said lowermost chamber.

4. An apparatus for drying grain, comprising an upright shaft having a grain supplying chamber near its top, a. grain delivering chambernear its bottom, a vacuum chamber intermediate the said top and bottom chambers, evacuating means for said vacuum chamber, means for opening and closing said vacuum chamber relativelyto said supplying chamber, the said vacuum chamber comprising three sections located one above the other and continuously communicating with one another, and heating means for the intermediate section, the uppermost section being constructed for storing the grain, the intermediate section for evaporating the humidity oi the grain, and the.

lowermost section for continuously'receiving the dried material from the intermediate section, and automatic intermittently-acting means for sup- I plying the grain to be dried and causing the dried grain to be delivered from said lowermost'section, in which hydraulicallyioperating means :are. provided for said opening and closing means.

5. An apparatus for} drying grain, comprising an upright shaft having a grain receiving chamber near its top, a grain delivering chamber near,

its bottom, a vacuum and heating chamber intermediate the said chambers, subsidiary chambers located respectively between said receiving and vacuum chambers and between saidvacuum and delivering chambers, 'means for opening and closing said subsidiary chambers relatively to said vacuum chamber and said receiving and delivering chambers respectively, means for heating and valve in said aperture, said valve having aconical skirt portion for scattering the material fed into the vacuum chamber, and means for opening and closing the valve. J I

'7. A device as in claim 6, said vacuum chamber including a storage section, a drying section below the storage section arranged to permit the mate-' rial under treatment to fiow only slowly therethrough, said valve-moving nieans including a motor, and means controlled by the grain in said storage section Ior controlling the action of the motor. H

8. In a drying apparatus, an upright shaft comprising a series of superposed chambers each having a downwardly tapered bottom with a aovaua central aperture, a valve in each such aperture, each valve having a conical form, and, common :means for moving said valves up and down to open and close said apertures.

5 9. A drying apparatus comprising an upright shaft, said shaft having a vacuum chamber, a storage chamber above the vacuum chamber, said storage chamber having an aperture in its bottom, a valve in said aperture, said vacuum chamber including asdrying section, a storage section above the drying section, and means for operating the valve including a member in said storagesection arranged to be held by the material in the said section.

'10. In a drying apparatus, an upright shaft comprising a series of superposed chambers with apertures 'at the bottom, including a vacuum chamber divided into an upper storage section, an intermediate drying section, and a lower receiving section, valves for saidapertures, and common means for opening and closing said valves including an electric motor controlled by material in said upper storage section for operating said switch.

11. In a drier for grain and the like, a shaft having avacuum chamber divided into an upper an intermediate drying section storage section, and a lower receiving section,'a receiving chamber above said vacuum chamber, valves respectively controlling the outlet from said-lower receiving section and a passage between said receiving chamber and said storage section, a rod connected to said valves, .an electric motor ar-' ranged to raise and lower said rod for opening and closing said valves, and a reversing switch for said motor, said switch being the material in said storage section.

12. In a drier for grain andthe like, a shaft storage section, an intermediate drying section and a lower receiving section, a receiving chamber above said vacuum chamber, a rod extending through saidshaft, valves operable by said rod. for controlling respectively the outlet from said lowerreceiving section and a passage leading from said receiving chamber to said-vacuum chamber, a nut threaded on said rod, an electric motor for turning said. nut, a reversing switch for said motor and means controlled by the material in said storage section for operating said switch.

' 13. In a drier for grain and the like, a shaft having a vacuum chamber-divided into an upper storage section, an intermediate drying section controlled by having a vacuum chamber divided into-an upper.

and a lower receiving section, a receiving chamber above said vacuum chamber, auxiliary vacuum chambers respectively below said lower receiving section, and between said receiving chamber, and said upper storage section, ports at the bottom of each chamber, a rod extending through said shaft, valves for said ports operable by movement of said rod to control the passage of material through said drier, an electric motor for actuating said rod, a reversing switch for said motor, and means controlled by the presence or absence .of material in said upper storage chamber for operating said switch;

14. In a drier for grain and the like,1a shaft having a vacuum chamber divided into an upper storage section, an intermediate drying section arranged to permit the material under treatment to flow only slowly therethrough anda lower receiving section, areceiving chamber above said vacuum chamber, auxiliary vacuum chambers respectively below said lower receiving section and between said receiving chamber and said upper storage sections, ports at the bottom of each chamber, a conical valve in each such port, and common means for moving said valves up and down to open and close said ports, including an electric motor for actuating said valve-moving means, and a, switch for said motor, the said switch being arranged to be opened by the presence of material in said upper storage section.

15. An apparatus for drying grain, comprising an upright shaft having a grain receiving chamber near its top, a grain delivering chamber near its bottom, a vacuum and heating chamber intermediate the said chambers, subsidiary chambers located respectively between said receiving and vacuum chambers and between said vacuum and delivering chambers, meansfor opening and ciosing said subsidiary chambers relatively to said vacuum chamberand said receiving and delivering chambers respectively, means for heating and evacuating said vacuum and heating chamber, means for evacuating said subsidiary cham bers, operating means for said opening and closing means, said vacuum chamber including a storage section, a drying section below the storage section arranged to permit the material under treatment to flow only slowly therethrough, said valve-moving means including a motor, and means controlled by the weight of grain in said storage sectionfor controlling the action of themotor. .KARL DIENST. 

